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REVIEW.—NATURAL HISTORY 
the size of the brain, compared with its nerves, affords an index 
of the differences existing between man and the lower animals, or 
between different animals, with regard to intellectuality, was an 
assumption unsupported by solid proof. 
He considers that the most striking characteristic of the human 
brain consists in the prodigious development of the cerebral hemi¬ 
spheres—no animal, whatever may be the proportion which the 
brain bears to the body, affording a parallel. Not any quadruped 
approaches man in the magnitude of the hemisphere of the brain; 
namely, that part of the organ which serves as the principal in¬ 
strument of the intellectual operations. Hence arises the cor¬ 
responding development of the anterior portion of the cranium; 
the index, at the same time, of the development of the cerebral 
hemispheres, and of their predominance over the portion of the 
cerebral mass devoted to the external senses; and hence, also, is 
the volume of the cranium in man greater, compared to that of the 
face, than in any other mammal. 
This part of the subject is illustrated by sketches, representing 
the upper surface of the brain of the chimpanzee, of the tigress, of 
the kangaroo, and of the wombat. 
The chimpanzee is the most anthropomorphous, or man-like, of 
the simiae, and accordingly we find an approach to man in the ge¬ 
neral form of the brain, and the proportions of its respective parts. 
Its general form, viewed from above, is a short oval, and the convo¬ 
lutions of the cerebral hemispheres are well marked. Neverthe¬ 
less, the cerebellum is not completely covered by the cerebrum, 
but projects beyond the posterior line of the latter, so as to be visi¬ 
ble, which, on reference to the brain of the human subject, will be 
found not to be the case in man. In the orang, the posterior pro¬ 
jection of the cerebellum is carried somewhat further. In the feline 
animals, of which the tiger is an example, the brain presents us 
with a still greater departure, in form and proportions, from that of 
man :—the cerebellum is completely posterior to the cerebral hemi¬ 
spheres, the comparative magnitude of which is diminished, not¬ 
withstanding the convolutions are strongly marked. The medulla 
oblongata has now acquired a greater volume, proportionately to the 
mass of the brain, than is found either in man or the chimpanzee. 
Descending lower in the scale, we at last arrive at the marsupial 
group. The kangaroo shews the cerebral hemispheres, not, per¬ 
haps, so diminished in bulk or narrowed anteriorly, and almost des¬ 
titute of convolutions on their surface. The cerebellum is remark¬ 
able for the development of its lateral lobes, and for the transverse 
striae with which it is marked. In the brain of the wombat, the 
central lobes are, in form and smoothness, like those of birds, 
and do not cover the enormous olfactory lobes or ganglions which 
